JPH10151982A - Carrying vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make loads so as not to be spilt in time of its transferring by tilting a vessel installed in an undercarriage of a travel body after displacing it in a direction where it should be surely transferred whenever these loads in the vessel are transferred. SOLUTION: A frame 4 connected with a vessel 3 through a connecting pin 5 is liftably installed in an undercarriage 2, and this vessel 3 is made tiltable as far as the specified angle to the frame 4 by a tilting hydraulic cylinder 15, while the frame 4 is connected to the undercarriage 2 via a cross-link 6, and a link plate 6a on one side is connected each to the undercarriage 2 and the frame 4 with two fulcrum pins 8 and 9, and two rollers 10 and 11 are connected to both ends of a link plate 6b on the other, making these rollers rollable along a horizontal guide member 12 horizontally installed in the undercarriage 2 and the frame 4, and when the vessel 3 is made to go or down by a lifting hydraulic cylinder 14, these rollers 10 and 11 are rolling toward the opposite direction each other along these horizontal guide members 12 and 13, and thereby the vessel 3 shifts in the horizontal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport vehicle for loading earth and sand, crushed materials, agricultural crops, and the like, and transferring them to predetermined transport means.

[0002]

2. Description of the Related Art For example, in civil engineering work, excavation of earth and sand and crushing of asphalt, concrete, and the like are performed in order to perform leveling, road repair, burial of sewer pipes and the like, and removal of structures. is there. This type of work is usually performed using a hydraulic excavator. A hydraulic excavator has a front working mechanism including a boom, an arm, and a front attachment. When a bucket is used as a front attachment in the front working mechanism, excavation of earth and sand can be performed, and earth and sand, rubble, and the like can be located in a certain place. Can be transferred to other places. In addition, if a crusher is mounted as a front attachment, asphalt on a road can be peeled off, and large lumps can be crushed. Further, if a breaker is mounted, concrete or the like can be broken.

[0003] Earth and sand, rubble, and the like discharged when performing the work of excavation, crushing, and the like with the above-described hydraulic excavator must be carried out of the work site using an appropriate transport means. A typical example of this transportation means is a dump truck. That is, the dump truck is disposed near the work site of the excavator at the work site, and the bucket in the front working mechanism of the excavator is operated to scoop up dirt, rubble, and the like and load the dump truck on the bed. When the dump truck is full of earth and sand, the dump truck is moved, a new dump truck is moved to a position where the earth and sand can be loaded by the hydraulic excavator, and this operation is sequentially repeated. Carry out work such as excavated earth and sand.

[0004]

In order to load excavated earth and sand from a hydraulic excavator onto a dump truck,
The dump truck must be able to enter the position where the excavator is actually operating. However, there are cases where the dump truck cannot approach the position where the excavator is operating due to various factors.

[0005] Work is performed even in a place where the dump truck cannot travel. 2. Description of the Related Art In recent years, in urban civil engineering, works such as leveling, digging trenches, and burying sewer pipes are performed on narrow roads such as alleys on which structures are present on both sides. In order to work in such a narrow place, an ultra-small hydraulic excavator called a so-called mini excavator is used. A large amount of earth and sand, rubble, etc. are discharged even by such mini excavator work, but if a large dump truck cannot enter this narrow place, sediment will be deposited at an appropriate place and It is necessary to take measures such as loading and unloading objects on a human-powered vehicle such as a cat car, and it is not possible to efficiently discharge the wastes, thereby reducing workability.

The dump truck travels on a general road, and has a structure suitable for traveling in a place where traveling conditions are good to some extent. For example, on a muddy land, a place where large debris or the like is scattered, or on other rough roads, the traveling may not be possible. Therefore, if the dump truck is unable to travel or is unsuitable for traveling in and around the work site, the dump truck cannot be brought into a position where objects to be carried out such as earth and sand and rubble can be loaded.

As described above, there are various restrictions on carrying out the earth and sand, rubble, and the like discharged at the work site such as the civil engineering work by the dump truck. There is an operation to carry out agricultural crops, but in order to perform this operation, it may not be possible to bring a transportation means such as a truck directly into the harvest site.

For example, Japanese Patent Application Laid-Open No. 6-127298 discloses a configuration of a self-propelled carrier. A dump mechanism is mounted on the carrier of this carrier, and in order to raise and lower the carrier from the vehicle body, a cross link is provided between the vehicle body and the carrier, and a cylinder is provided. Is configured to be able to move up and down. And, depending on whether one of the slide moving parts in the cross link is guided in the horizontal direction or in the inclined direction,
The user can select whether to lift the bed straight upward or to swing it upward diagonally.

[0009] However, in this conventional vehicle having a carrier with a dump mechanism in the prior art, although it can be loaded on the carrier and moved from one place to another, it is difficult to transfer it to a dump truck or the like. It has an unsuitable structure. That is, when a truck is arranged at a position very close to the carrier of the dump truck and the carrier of the carrier swings upward, during the swing operation,
Since the load starts to fall from just before the upper position of the dump truck's bed, there is a disadvantage that a certain amount of the load spills between the carrier and the dump truck.

The present invention has been made in view of the above points, and an object of the present invention is to tilt a vessel after displacing the vessel in the direction of a portion to be surely transferred. Another object of the present invention is to make it possible to transfer a load to a transportation means or the like without causing the load to spill in the dark.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a lifting and lowering and tilting operation of a vehicle having a predetermined loading capacity and an open upper part connected to a traveling means. The vessel is mounted so as to be capable of being provided between the vessel side and the chassis side, elevating means for elevating and lowering the vessel and tilting means for inclining the vessel, and elevating means, when the vessel is raised, one direction And a horizontal guide means for horizontally moving toward.

Here, the vessel is provided so that one end or the vicinity of the end is tiltably connected to the vessel supporting member, and the vessel supporting member and the vessel are moved up and down by means of lifting and lowering. In this manner, the tilting means can tilt the vessel with respect to the vessel support member. Elevating means, elevating drive means, a pair of link plates provided between the chassis and the vessel support member, one of the link plates is pivotally attached to the chassis side and the vessel side, respectively, a cross link,
The chassis and the vessel support member are provided in a horizontal direction,
Horizontal guide means for guiding both ends of the other link plate of the cross link so as to be movable in opposite directions when the vessel is raised and lowered can be provided. In this case, the tilting means is interposed between the vessel and the vessel support member. Further, one end of the lifting / lowering drive means is connected to the chassis, but the other end can be connected to one link plate or frame of the cross link.

The moving direction of the vessel in the horizontal direction is always constant. Therefore, in order to enable the vessel to move horizontally in any direction, the chassis is configured to be able to turn with respect to the traveling means. The traveling means may be a wheel type, but is composed of a crawler type traveling body having a pair of left and right crawler tracks in case of traveling in a place where traveling conditions are extremely bad, such as muddy land. Is preferred. Further, the work to be loaded on the vessel of the transport vehicle can be performed using a working machine such as a hydraulic shovel, but is configured as a transport vehicle with a so-called working mechanism that causes the transport vehicle itself to perform the load operation on the vessel. It is also possible. For this purpose, a front working mechanism including a boom, an arm and a bucket is installed on a chassis, and the front working mechanism is mounted on a rotating base that can rotate at least 180 ° with respect to the chassis. Further, a driver's seat may be installed on the rotating base together with the operation means. Further, in order to perform a work such as digging a gutter, the front working mechanism is provided with an offset mechanism.

[0014]

Embodiments of the present invention will be described below. First, FIG. 1 to FIG. 4 show a basic configuration of a transport vehicle. As shown in FIG. 1, the transport vehicle includes a traveling unit 1;
It is schematically composed of a chassis 2 provided above the traveling means 1 and a vessel 3 which can be moved up and down with respect to the chassis 2.

The vessel 3 is composed of an open-top container on which earth and sand can be loaded in a predetermined capacity. As shown in FIGS. 2 to 4, the vessel 3 has one end with respect to a frame 4 as a vessel support member. The side is connected by a connecting pin 5 so as to be rotatable in the vertical direction, and is always kept in a horizontal state. From this horizontal state, the connecting pin 5 can be tilted at a predetermined angle with respect to the frame 4 around the connecting pin 5. .

The frame 4 is connected to the chassis 2 via a cross link 6. Cross link 6
It has a pair of link plates 6a and 6b.
a and 6b are of the same length, and are rotatably connected to each other by a connecting pin 7 at an intermediate position thereof, preferably at a position equally divided into two. The lower end of one link plate 6a is pivotally attached to the chassis 2 by a pivot pin 8, and the upper end is pivotally attached to the frame 4 by a pivot pin 9. On the other hand, the roller 1 is provided at both ends of the other link plate 6b.
0 and 11 are connected to each other.
Numerals 0 and 11 can be rolled along horizontal guide members 12 and 13 extending horizontally to the chassis 2 and the frame 4, respectively. Accordingly, when the cross link 6 is operated, the rollers 10 and 11 roll in opposite directions along the horizontal guide members 12 and 13, respectively.

Between the chassis 2 and the link plate 6a of the cross link 6, an elevating hydraulic cylinder 14 as an elevating drive means is interposed.
4, the cross link 6, and the horizontal guide members 12, 13 constitute elevating means. A tilt hydraulic cylinder 15 is interposed between the frame 4 and the vessel 3, and the tilt hydraulic cylinder 15 is a tilt unit that tilts the vessel 3. Here, the lifting hydraulic cylinder 14
, And the connecting portions of the tilting hydraulic cylinder 15 to the frame 4 and the vessel 3 are both pivotable.

With the above structure, when the lifting hydraulic cylinder 14 and the tilting hydraulic cylinder 15 are both held in a contracted state, the vessel 3 is positioned almost directly above the chassis 2 as shown in FIG. The lowermost position, that is, the loading position of the load.

In this state, when the lifting hydraulic cylinder 14 is extended, the cross link 6 provided between the chassis 2 and the frame 4 is operated, and the frame 4 to which the vessel 3 is connected rises. However, the frame 4 does not rise straight, but the link plate 6a of the cross link 6 shows a pivoting movement about the pivot pin 8 as a fulcrum. In other words, the vessel 3 is moved so that the side of the vessel 3 connected to the frame 4 is forward in the traveling direction. At this time, the other link plate 6b
The rollers 10 and 11 provided at both ends of the link plate 6 move in the horizontal direction along the horizontal guide members 12 and 13, respectively, and also move in the direction away from each other. And the height position of the roller 11 are always kept in the same state. Therefore, the frame 4 and the vessel 3 rise and move in the horizontal direction, and as shown in FIG. 3, the vessel 3 rises from the chassis 2 and horizontally moves in a direction away from the chassis 2. The position of the extension stroke end of the lifting hydraulic cylinder 14 is the rising position of the vessel 3.

When the tilt hydraulic cylinder 15 is extended at the position where the vessel 3 is raised, the vessel 3 tilts around the connecting pin 5 such that the free end is lifted up with respect to the frame 4. Become. by this,
The vessel 3 is displaced to the transfer position shown in FIG. Here, the position of the connecting portion of the vessel 3 to the frame 4 by the connecting pin 5 is the front position in the horizontal movement direction when the vessel 3 is raised, and this portion is the chassis 2.
It is the position farthest from.

Accordingly, the vessel 3 is set to the loading position shown in FIG. 2, and the vessel 3 is loaded with earth and sand, rubble, etc., and is located at a position close to the dump truck T as shown in FIG. When the hydraulic cylinder 14 for raising and lowering is actuated, the vessel 3 rises from the chassis 2 and moves horizontally above the bed B of the dump truck T by the action of the cross link 6. . Therefore, as shown in FIG.
It is placed in the upper position. When the tilting hydraulic cylinder 15 is actuated after the vessel 3 is at the raised position, FIG.
As shown in (1), the vessel 3 is tilted so that the other side is lifted up around a portion connected to the frame 4 by the connecting pin 5. Thereby, the vessel 3
Can be transferred to the carrier B. Here, in order to carry out the transfer from the vessel 3 more smoothly and reliably, the opening / closing plate 3a is provided on the side surface of the vessel 3 on the side connected to the connection pin 5.
So that the opening / closing plate 3a can perform a tilting operation about the upper end side. As a result, the load in the vessel 3 can be reliably and completely transferred to the carrier B, and the load does not spill to the front side of the carrier B of the dump truck T during the transfer.

Here, the transport vehicle is used, for example, to travel in a place where the dump truck T is not suitable for traveling and to transfer the load to the dump truck T. The running conditions are not bad, but when running in narrow places, the running means may be wheel type, but for running on bad roads or muddy land where rubble and others are scattered, FIG.
As shown in FIG.
A crawler-type traveling body composed of a crawler belt 1c wound and provided between a and the idler 1b is provided. The use of a so-called rubber crawler belt formed of rubber, which is an elastic member, as the crawler belt 1c is advantageous for running on a rough road and reducing the weight of the entire vehicle.

When the vessel 3 is at the raised position, it is also displaced in the horizontal direction, but this displacement direction is one direction.
However, it is more convenient to carry out the transfer operation by providing a variation in the direction in which the load is transferred from the vessel 3. For this purpose, a turning device 16 is interposed between the traveling means 1 and the chassis 2. The turning device 16 is provided between a traveling body frame that supports a pair of right and left crawler traveling bodies that constitute traveling means and a chassis frame of the undercarriage 2, has an outer wheel and an inner wheel, and has an inner surface on the inner surface side of the inner wheel. A well-known turning device provided in a normal working machine can be used in which a gear is formed, a pinion driven by a turning hydraulic motor is mounted on the chassis frame side, and the pinion is meshed with the gear. . As described above, when the chassis 2 provided with the vessel 3 is rotatable, for example, when the carrier B of the dump and the rack T is located on the side in the traveling direction of the carrier, the dump truck T By rotating the chassis 2 at a predetermined angle at a position close to the vehicle, the transfer of the load from the vessel 3 to the carrier B can be performed smoothly.

As described above, when the transport vehicle has a structure suitable for traveling in a narrow place, it is necessary to form the entirety of the transport vehicle as compact as possible. For this purpose, equipment necessary for the operation of the transport vehicle, that is, equipment such as an engine and a hydraulic pump, is installed in a machine room 17 provided in the undercarriage 2. The structure can be operated by a remote control method. As a result, the vessel 3 which is compact and has a large capacity can be used because the operator cab is not provided, and the transport of the load in a narrow place can be performed very efficiently.

In the above-described embodiment, the transport vehicle is configured so that the load can be transported from one location to another location and transferred to the dump truck T or the like. It is also possible to configure as a transport vehicle with a working mechanism that can load earth and sand, rubble, and the like on the vessel 3. To this end, the transport vehicle is configured as shown in FIG. In FIG. 5, the same or equivalent members as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 5, reference numeral 20 denotes a turning base. The turning base 20 is mounted on the chassis 2 so as to be able to turn in the horizontal direction by the same mechanism as that of the turning device 16 described above. Have been. Further, a front working mechanism 21 is installed on the rotating base 20. Front working mechanism 21
Is a boom 22 which is connected to the rotating base 20 so as to be capable of raising and lowering, an arm 23 which is connected to the tip of the boom 22 so as to be able to rotate in the vertical direction, and And a bucket 24 connected as possible.
A boom cylinder 25 is provided between the boom 22 and the rotation base 20, an arm cylinder 26 is provided between the boom 22 and the arm 23, and an arm 23 and the bucket 2 are provided.
The bucket cylinders 27 are connected to each other. The above configuration is the same as that of the front working mechanism of the hydraulic shovel installed on the upper-part turning body, and therefore illustration and description of the detailed mechanism are omitted.

As described above, the front working mechanism 2 is attached to the transport vehicle.
By providing 1, for example, excavation of earth and sand,
The excavated earth and sand is loaded on the vessel 3, and when the vessel 3 is full of earth and sand, the excavated earth and sand can be self-propelled to a place where the dump truck T and the like are arranged, and can be transferred to the carrier. That is, when the front working mechanism 21 is disposed at the position shown by the solid line in FIG. 5, it is possible to perform work such as excavation of earth and sand.
When the earth and sand are excavated, the arm 23 is folded toward the boom 22 and the turning base 20 is turned by approximately 180 °. As shown by the imaginary line in FIG. When the bucket 24 is operated in this state, the earth and sand accommodated in the bucket 24 can be loaded on the vessel 3. here,
When performing operations such as excavation of earth and sand and loading of excavated earth and sand, it is sufficient that the turning base 20 is turned at least substantially 180 °, so that the turning base 20 is turned. The drive to be performed does not have the same configuration as the turning device, and for example, a crank mechanism or the like can be used.

In the case where the transport vehicle is configured as a transport vehicle having a working mechanism for performing operations such as excavation of earth and sand by the front working mechanism 21 in addition to simply transporting and transferring the load, wireless communication is used. The operation may be performed by a remote control method, but it is preferable that the operation is performed by an operator on board in terms of work efficiency and the like. For this purpose, as shown in FIG.
In addition to the front working mechanism 21, a driver's seat 30 and an operating means 31 such as an operating lever provided around the driver's seat 30 are installed on a rotating base 20 that is rotatably installed above. Thereby, the driver's seat 30 and the front working mechanism 2
1 is always maintained in the same positional relationship, so that when performing excavation work, the driver's seat 30 faces the direction of the excavation position, and when loading on the vessel 3, the driver's seat 30 It turns to the direction. Therefore, in performing these combined operations, each operation can be performed smoothly, and the safety of the operations can be ensured.

By the way, in a transport vehicle with a working mechanism provided with a front working mechanism 21 capable of excavating work, the transport vehicle is digged on a narrow road such as an alley and the excavated soil is loaded on the vessel 3. Thus, a series of operations of transferring the dump truck T to the bed B of the dump truck T waiting on a wide road can be performed.

For this purpose, as described above, the traveling means 1 is configured as a crawler-type traveling body having a rubber crawler, and a rotating base 20 is installed on the chassis 2 so that The table 20 is provided with a front working mechanism. Further, a driver's seat may be provided on the rotating base 20 as necessary. Here, a front working mechanism 40 with an offset mechanism as shown in FIGS. 7 and 8 is used as the front working mechanism. Front working mechanism 4 with this offset mechanism
Reference numeral 0 denotes a first boom 41 which is connected to the rotating base 20 so as to be capable of raising and lowering, and is connected to the first boom 41 via a first horizontal rotating shaft 42 so as to be rotatable in the horizontal direction. A boom is constituted by the second boom 43 and a support bracket 45 connected to the end of the second boom 43 via a second horizontal rotation shaft 44 so as to be rotatable in the horizontal direction. It is connected so that it can rotate vertically. Further, a bucket 47 is connected to the tip of the arm 46. A boom cylinder 48 is provided between the rotation base 20 and the first boom 41.
And an arm cylinder 49 between the support bracket 45 and the arm 46, and furthermore, an arm 46 and a bucket 47.
Are connected to each other between the bucket cylinders 50.

The second boom 43 can rotate horizontally by a predetermined angle with respect to the first boom 41. The axes of the support bracket 45, the arm 46, and the bucket 47 are such that the second boom 43 moves in the horizontal direction. Even if it rotates, it is maintained in a state parallel to the axis of the first boom 41. An offset hydraulic cylinder 51 is provided between the first boom 41 and the second boom 43 to rotate the second boom 43 about the first horizontal rotation shaft 42.
In addition, even if the second boom 43 is rotated in the horizontal direction, the first boom 41 and the support bracket are maintained in order to keep the axes of the support bracket 45, the arm 46, and the bucket 47 parallel to the axis of the first boom 41. 45, the mounting plate 41a,
45a are provided so as to extend, respectively.
A connecting rod 52 is bridged between a and 45a. The connecting rod 52, the mounting plates 41a, 45a and the second boom 43 constitute a parallelogram link mechanism.

By mounting the above-mentioned front working mechanism 40 on the turning base 20 and operating the offset hydraulic cylinder 51 to turn the second boom 43 by a predetermined angle, the support bracket 45, The arm 46 and the bucket 47 move parallel to the axis of the first boom 41, and the position of the bucket 47 is offset by this movement amount ΔD. As a result, the bucket 47 can be arranged at a position deviated to the side of the chassis 2, and by digging with this bucket 47, it is possible to dig a ditch along the boundary between the road and the building or the like.

The earth and sand excavated by the bucket 47 is rotated by rotating the rotation base 20 in the horizontal direction, so that the vessel 3
Digging can be continued until the vessel 3 is full of earth and sand. And Vessel 3
When the dump truck T is self-propelled to the position where the dump truck T is on standby and operates the hydraulic cylinder 14 for raising and lowering, the vessel 3 loaded with soil is raised, It moves horizontally in the direction of the upper position of the bed B. When the tilt hydraulic cylinder 15 is actuated after reaching the raised position, the vessel 3 is tilted about the connection pin 5 of the frame 4 as a result,
Fully loaded earth and sand can be transferred from the vessel 3 to the bed B of the dump truck T. Therefore, when the vessel 3 is emptied after the earth and sand are transferred, it is possible to return to the work site again and continue the digging. When the horizontal moving direction at the time of raising the vessel 3 is different from the position of the bed B of the dump truck T, the turning device 16 is operated to turn the chassis 2 by a predetermined angle, and the horizontal moving of the vessel 3 is performed. Dump truck T in the direction
Can be changed so that the bed B of the vehicle is located.

[0034]

As described above, according to the present invention, the vessel is provided with the elevating means for elevating and lowering and the tilting means for inclining the vessel, and when the vessel is raised by the elevating means, the vessel is moved in one direction. , So that the vessel is securely displaced in the direction of the part to be transferred, and by tilting the vessel, the load does not spill in the dark during transfer. And so on.

[Brief description of the drawings]

FIG. 1 is a side view of a transport vehicle showing an embodiment of the present invention.

FIG. 2 is an operation explanatory view showing an operation state of the vessel in the transport vehicle of FIG. 1 in which the traveling means is omitted, in which the vessel is arranged at a loading position.

FIG. 3 is an operation explanatory view in a state where a vessel is arranged at a raised position.

FIG. 4 is an operation explanatory view in a state where a vessel is arranged at a transfer position.

FIG. 5 is a side view of a transport vehicle equipped with a work mechanism provided with the work mechanism.

FIG. 6 is a front view showing a transport vehicle with a working mechanism provided with a driver's seat.

FIG. 7 is a side view showing a state in which a front working mechanism having an offset mechanism is mounted on a transport vehicle with a working mechanism.

FIG. 8 is a plan view of a front working mechanism having an offset mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Running means 2 Undercarriage 3 Vessel 4 Frame 5 Connecting pin 6 Cross link 6a, 6b Link board 7 Connecting pin 8,9 Pivot pin 10,11 Roller 12,13 Horizontal guide means 14 Elevating hydraulic cylinder 15 Tilting hydraulic cylinder 16 Turning device 21 Rotating base 21, 40 Front working mechanism 30 Driver's seat 31 Operating means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akinao Komori 650, Kandamachi, Tsuchiura-shi, Ibaraki Pref.

Claims (7)

[Claims] 1. A vehicle having a predetermined loading capacity and an open-top vessel mounted on a chassis connected to a traveling means so as to be able to move up and down and tilt, wherein a vessel is provided between the vessel side and the chassis side. An elevating means for elevating and lowering the vessel and an inclining means for inclining the vessel, wherein the elevating means comprises horizontal guide means for horizontally moving in one direction when the vessel is raised. Haul truck. 2. The vessel according to claim 1, wherein one end or the vicinity of the end is connected to the vessel support member so as to be tiltable, and a tilting means is provided between the vessel support member and the vessel. The lifting / lowering means includes a lifting / lowering drive means, and a pair of link plates provided between the chassis and the vessel support member, one of the link plates being pivotally connected to the chassis side and the vessel side, respectively; And horizontal guide means provided in the vessel support member in a horizontal direction, and guides both ends of the other link plate of the cross link so as to be movable in opposite directions when the vessel is raised and lowered. The transport vehicle according to claim 1. 3. The transportation vehicle according to claim 1, wherein said traveling means is a crawler traveling body having a pair of right and left crawler tracks. 4. The transport vehicle according to claim 1, wherein the undercarriage is configured to be pivotally connected to the traveling means via a pivoting device. 5. A structure in which a turning base is provided on the chassis, and a front working mechanism comprising a boom, an arm, and a bucket is mounted on the turning base, so that the turning base can be turned at least 180 °. The carrier according to claim 1, wherein: 6. The transportation vehicle according to claim 5, wherein a driver's seat and operation means are provided on the rotating base together with the front working mechanism. 7. The transportation vehicle according to claim 6, wherein the front working mechanism includes an offset mechanism.